body {
    margin: 0;
    overflow: hidden;
    background: linear-gradient(to bottom, #19778c, #095f88);
    background-size:1400% 300%;
    animation: dynamics 6s ease infinite;
    -webkit-animation: dynamics 6s ease infinite;
    -moz-animation: dynamics 6s ease infinite;
    font-size: 14px;
    /*color: #ffffff;*/
    min-height: 700px;
}
/*登录样式*/
.main {
    position: fixed;
    text-align: center;
    width: 100%;
    height: auto;
    display: flex;
    justify-content: center;
}

@keyframes dynamics {
    0% {
        background-position: 0% 0%;
    }
    50% {
        background-position: 50% 100%;
    }
    100% {
        background-position: 100% 0%;
    }
}
/*版权样式*/
.copyright a{
    position: fixed;
    bottom: 10px;
    font-size: 16px;
    display: block;
    width: 100%;
    text-align: center;
    color: white;
}